With just over a week to go before Apple is expected to announce an official macOS 10.12 Sierra release date, the company on Monday issued the latest beta versions of the operating system to developers and public beta testers for evaluation.

Today's seeds come just hours after Apple sent out media invites for a special event on Sept. 7, at which the company is expected to unveil a set of new iPhone models. Traditionally, Apple's September events coincide with the release of new operating systems for iOS and Mac.

As for the beta versions, Apple's release notes contain no major changes or additions beyond ongoing bug fixes and performance improvements. Apple's most recent set of macOS Sierra betas released last week included a string of code referencing SuperSpeed+ support up to 10 gigabits per second, suggesting forthcoming Mac hardware will support the USB 3.1 Gen 2 standard.

Announced at the Worldwide Developers Conference in June, macOS Sierra promises a number of enhancements including a desktop version of Apple's Siri virtual assistant, as well as integration with Apple Pay for the web.

Developers can download macOS Sierra from Apple's Developer Portal or directly from the Mac App Store. Like past macOS Sierra builds, support for the latest beta version is limited to late-2009 or newer MacBooks and iMacs, and 2010 or newer MacBook Air, MacBook Pro, Mac mini and Mac Pro models.